Background. Regular physical activity and obesity are both independent risk factors for type 2 diabetes. Interventions to promote physical activity implemented at each of the Individual, Interpersonal, and Community levels show promise but their combination has not been evaluated over more than short time periods. Through ongoing projects in southeast Missouri, walking trails have been built in numerous communities, yet trails have not been widely promoted. Aim Evaluate the effectiveness of a study integrating individual, interpersonal, and community-level interventions to promote walking among overweight, rural adults, including those at high risk for diabetes. In addition to investigating diabetes prevention in this high priority population, the project will be generalizable to other settings in which promoting physical activity is a priority. Methods and Evaluation. A randomized, controlled design will randomize 16 local communities with existing walking trails to either intervention or control condition. Based on the ecological framework, multi-level interventions will include: Individual Level -- tailored newsletters; Interpersonal Level - promotion of walking and use of trails through primary care providers; and Community Level -- newsletters, contests, and varied promotional activities planned and implemented through a Community Steering Committee. Evaluation cohorts of overweight (BMI equal to or >25) adults recruited through random digit dialed population surveys will be used to assess impacts on walking, overweight, and HbAl(c) at baseline, 12, and 24 months. Additional process evaluations will include unobtrusive counts of walkers (using infrared devices and card readers) and event logs to characterize program impacts and contributions of specific program components. Innovations and Dissemination. This study is innovative because it promotes and evaluates an important multi-level intervention, makes use of extensive pilot data, focuses on a population at high risk of diabetes, uses a multi-tiered evaluation plan, advances the field regarding measurement of physical activity, and takes advantage of new information technologies (e.g., computerized tailoring, GIS mapping). Study findings will be disseminated in collaboration with co- investigators, federal agencies, and other public health agencies to a variety of professional audiences.